political effects, asking such questions as: (a) How are these population changes perceived and to what extent do they have political effects irrespective of the ways in which they are perceived? (b) In what ways does the cultural, social, and economic environment shape the political effects of population changes, and do the demographic changes have an independent and direct political consequence? (c) How are demands upon the political and administrative framework affected by population changes? (d) And finally, what are the effects of these population changes on the political and social interaction of groups and the distribution of political power within the society?
Political Effects of Changes in Age Structure
Three factors affect the age of a nation's population. The first and most important is simply the number of children women bear. An increase in the number of births will produce a younger population. The second is a drop in the death rate, which favors young people more often than the elderly. A decline in the death rate most often benefits infants and small children. For example, in Sweden 95 percent survive from birth to age 30 today, as compared to 67 percent in 1870 (30). The third factor is the migration rate. Since migrants tend to be young, a large immigration rate generally means a younger population, and a large emigration generally means an older population.
In many countries in the developing areas, fertility rates are higher, mortality rates are lower, and emigration rates less than was the case for many western European countries in the 19th century. Health conditions improved slowly in many European countries, birthrates were often lower, and migration to North and South America was great. In both the 18th and 19th centuries, most European countries had older populations than exist in most developing countries today. And the contrast between the age structure of Asia, Africa, and Latin America and that of the developed world today is quite striking. For example, 47 percent of the Philippine population is below the age of 15, in contrast to only 23 percent of the British population. Half the population of the Congo is under 20, and half of Brazil is under 19.
Wars have also had a substantial effect on the age structure of a population. In World War I, Serbia lost 27 percent of its males between the ages of 15 and 49, Russia lost 16 percent, Turkey 15 percent, Romania 14 percent, and France 13 percent (31). An extended war may also eliminate a generation of infants who would have been born had there been no war. In a society in which women give birth at frequent intervals, the temporary removal of a large number of males will have a permanent effect on population size. But in a society in which family planning is common, war may only lead to a postponement in births with the result that the end of the war is accompanied byICAL DEMOGRAPHY